1. Technical Field
The present invention relates to a direct ink storage type writing implement with an ink collector, having an ink chamber disposed at the rear part of the barrel cylinder for directly storing the ink and an ink collector mounted at the front part of the barrel cylinder.
2. Background Art
In general, a typical direct ink storage type writing implement has an ink chamber for directly storing the ink, instead of occluding the ink with a sliver or the like and also has an ink collector which temporarily retains the ink in order to prevent the ink, which is pushed out from the ink chamber when the air in the ink chamber expands due to a temperature rise, from blotting from the pen point or air holes. The writing implements are usually applied to marking pens, ball-point pens and the like.
The ink used in such a direct ink storage type writing implement is typically a water-based ink, including a coloring material made up of pigments and/or dyes, a solvent such as ethylene glycol, glycerin, propylene glycol and the like, water and other additives for writing implements.
The ink collector in a conventional writing implement has a passage hole therein in which an ink conduit core for conveying the ink from the ink chamber to the pen point is provided. This ink conduit core is press fitted or loosely fitted with some gap at the rear part of the passage hole of the ink collector. When this writing implement is oriented downwards or is laid laterally immediately after its assembly, the rear part of the ink collector and the rear end of the ink conduit core are wetted with ink so that the ink collector will be sealed at its rear end with ink.
Because of this sealing, the passage hole communicates with the atmosphere only by way of the pen tip. Therefore, as the ink from the ink chamber permeates through the capillaries of the ink conduit core and reaches the pen tip, the ink pushes the air inside the capillaries of the ink conduit core forwards so that the air thus pushed is discharged from the tip of the pen point while the space, or the capillaries, of the ink conduit core is filled up with ink, finally allowing writing.
However, once this state is established, particularly for the case of an writing implement having as its writing tip a ball point, the space between the pen point holder and the tip is filled up with ink so that the gap between the passage hole of the ink collector and the ink conduit core becomes confined.
In this situation, if this writing implement is left under an atmosphere of 0xc2x0 C. or below, the water-based ink will freeze inside the writing implement, expanding its volume, consequently the unfrozen solvent is pushed out from the pen tip by the volume expansion, soiling the pen tip.
Further, in the conventional ink collector, the air inside the ink conduit core needs to be pushed out from the tip of the pen point from when the writing implement is assembled until the ink, passing through the ink conduit core, reaches the pen tip. In particular, for the case of a writing implement having as its writing tip a ball point, the clearance between the ball and the ball holder is so small that it is hard to release the air which is pushed from the rear by the ink. As a result, it takes a long time for the ink to reach the tip of the pen point. Because it takes a long time before the writing test of the writing implement after the assembly of the writing implement, it is impossible to increase the total production rate even if the assembly rate of the writing implement is increased.
Moreover, in order to enhance the assembly rate, there is an idea that the writing implement after assembly is held still, temporarily until the ink reaches the pen tip. However, this method has the drawback of the assembling machine being complicated.
In view of the above conventional drawbacks and to solve them, it is an object of the present invention to provide a direct ink storage type writing implement with an ink collector, which is able to prevent the solvent etc., contained in the ink from being pushed out from its pen tip when the writing implement has been left under the atmosphere of 0xc2x0 C. or below and hence prevent soiling at its pen point and of which the assembling machine can be simplified with its productivity improved.
The inventors hereof have earnestly studied about the above conventional drawbacks, and have found a particular flank configuration of the ink collector having a passage hole in which the ink conduit core for supplying ink from the ink chamber to the pen tip is arranged, and finally have completed a writing implement with an ink collector which satisfies the above object.
That is, a writing implement with an ink collector of the present invention is a direct ink storage type writing implement comprising:
an ink chamber disposed at the rear part of the barrel cylinder for directly storing the ink; and
an ink collector mounted at the front part of the barrel cylinder, and is characterized in that the ink collector is formed with a passage hole therein in which an ink conduit core for conveying the ink from the ink chamber to the pen point is provided while the flank of the ink collector is formed with air holes that communicate with the passage hole.